1 /*
2  * Copyright (C) 2014 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 package android.app;
17 
18 import android.os.Bundle;
19 import android.os.ResultReceiver;
20 import android.transition.Transition;
21 import android.util.SparseArray;
22 import android.view.View;
23 import android.view.ViewGroup;
24 import android.view.ViewTreeObserver;
25 import android.view.Window;
26 
27 import java.lang.ref.WeakReference;
28 import java.util.ArrayList;
29 
30 /**
31  * This class contains all persistence-related functionality for Activity Transitions.
32  * Activities start exit and enter Activity Transitions through this class.
33  */
34 class ActivityTransitionState {
35 
36     private static final String ENTERING_SHARED_ELEMENTS = "android:enteringSharedElements";
37 
38     private static final String EXITING_MAPPED_FROM = "android:exitingMappedFrom";
39 
40     private static final String EXITING_MAPPED_TO = "android:exitingMappedTo";
41 
42     /**
43      * The shared elements that the calling Activity has said that they transferred to this
44      * Activity.
45      */
46     private ArrayList<String> mEnteringNames;
47 
48     /**
49      * The names of shared elements that were shared to the called Activity.
50      */
51     private ArrayList<String> mExitingFrom;
52 
53     /**
54      * The names of local Views that were shared out, mapped to those elements in mExitingFrom.
55      */
56     private ArrayList<String> mExitingTo;
57 
58     /**
59      * The local Views that were shared out, mapped to those elements in mExitingFrom.
60      */
61     private ArrayList<View> mExitingToView;
62 
63     /**
64      * The ExitTransitionCoordinator used to start an Activity. Used to make the elements restore
65      * Visibility of exited Views.
66      */
67     private ExitTransitionCoordinator mCalledExitCoordinator;
68 
69     /**
70      * The ExitTransitionCoordinator used to return to a previous Activity when called with
71      * {@link android.app.Activity#finishAfterTransition()}.
72      */
73     private ExitTransitionCoordinator mReturnExitCoordinator;
74 
75     /**
76      * We must be able to cancel entering transitions to stop changing the Window to
77      * opaque when we exit before making the Window opaque.
78      */
79     private EnterTransitionCoordinator mEnterTransitionCoordinator;
80 
81     /**
82      * ActivityOptions used on entering this Activity.
83      */
84     private ActivityOptions mEnterActivityOptions;
85 
86     /**
87      * Has an exit transition been started? If so, we don't want to double-exit.
88      */
89     private boolean mHasExited;
90 
91     /**
92      * Postpone painting and starting the enter transition until this is false.
93      */
94     private boolean mIsEnterPostponed;
95 
96     /**
97      * Potential exit transition coordinators.
98      */
99     private SparseArray<WeakReference<ExitTransitionCoordinator>> mExitTransitionCoordinators;
100 
101     /**
102      * Next key for mExitTransitionCoordinator.
103      */
104     private int mExitTransitionCoordinatorsKey = 1;
105 
106     private boolean mIsEnterTriggered;
107 
ActivityTransitionState()108     public ActivityTransitionState() {
109     }
110 
addExitTransitionCoordinator(ExitTransitionCoordinator exitTransitionCoordinator)111     public int addExitTransitionCoordinator(ExitTransitionCoordinator exitTransitionCoordinator) {
112         if (mExitTransitionCoordinators == null) {
113             mExitTransitionCoordinators =
114                     new SparseArray<WeakReference<ExitTransitionCoordinator>>();
115         }
116         WeakReference<ExitTransitionCoordinator> ref = new WeakReference(exitTransitionCoordinator);
117         // clean up old references:
118         for (int i = mExitTransitionCoordinators.size() - 1; i >= 0; i--) {
119             WeakReference<ExitTransitionCoordinator> oldRef
120                     = mExitTransitionCoordinators.valueAt(i);
121             if (oldRef.get() == null) {
122                 mExitTransitionCoordinators.removeAt(i);
123             }
124         }
125         int newKey = mExitTransitionCoordinatorsKey++;
126         mExitTransitionCoordinators.append(newKey, ref);
127         return newKey;
128     }
129 
readState(Bundle bundle)130     public void readState(Bundle bundle) {
131         if (bundle != null) {
132             if (mEnterTransitionCoordinator == null || mEnterTransitionCoordinator.isReturning()) {
133                 mEnteringNames = bundle.getStringArrayList(ENTERING_SHARED_ELEMENTS);
134             }
135             if (mEnterTransitionCoordinator == null) {
136                 mExitingFrom = bundle.getStringArrayList(EXITING_MAPPED_FROM);
137                 mExitingTo = bundle.getStringArrayList(EXITING_MAPPED_TO);
138             }
139         }
140     }
141 
saveState(Bundle bundle)142     public void saveState(Bundle bundle) {
143         if (mEnteringNames != null) {
144             bundle.putStringArrayList(ENTERING_SHARED_ELEMENTS, mEnteringNames);
145         }
146         if (mExitingFrom != null) {
147             bundle.putStringArrayList(EXITING_MAPPED_FROM, mExitingFrom);
148             bundle.putStringArrayList(EXITING_MAPPED_TO, mExitingTo);
149         }
150     }
151 
setEnterActivityOptions(Activity activity, ActivityOptions options)152     public void setEnterActivityOptions(Activity activity, ActivityOptions options) {
153         if (activity.getWindow().hasFeature(Window.FEATURE_ACTIVITY_TRANSITIONS)
154                 && options != null && mEnterActivityOptions == null
155                 && mEnterTransitionCoordinator == null
156                 && options.getAnimationType() == ActivityOptions.ANIM_SCENE_TRANSITION) {
157             mEnterActivityOptions = options;
158             mIsEnterTriggered = false;
159             if (mEnterActivityOptions.isReturning()) {
160                 restoreExitedViews();
161                 int result = mEnterActivityOptions.getResultCode();
162                 if (result != 0) {
163                     activity.onActivityReenter(result, mEnterActivityOptions.getResultData());
164                 }
165             }
166         }
167     }
168 
enterReady(Activity activity)169     public void enterReady(Activity activity) {
170         if (mEnterActivityOptions == null || mIsEnterTriggered) {
171             return;
172         }
173         mIsEnterTriggered = true;
174         mHasExited = false;
175         ArrayList<String> sharedElementNames = mEnterActivityOptions.getSharedElementNames();
176         ResultReceiver resultReceiver = mEnterActivityOptions.getResultReceiver();
177         if (mEnterActivityOptions.isReturning()) {
178             restoreExitedViews();
179             activity.getWindow().getDecorView().setVisibility(View.VISIBLE);
180         }
181         mEnterTransitionCoordinator = new EnterTransitionCoordinator(activity,
182                 resultReceiver, sharedElementNames, mEnterActivityOptions.isReturning());
183 
184         if (!mIsEnterPostponed) {
185             startEnter();
186         }
187     }
188 
postponeEnterTransition()189     public void postponeEnterTransition() {
190         mIsEnterPostponed = true;
191     }
192 
startPostponedEnterTransition()193     public void startPostponedEnterTransition() {
194         if (mIsEnterPostponed) {
195             mIsEnterPostponed = false;
196             if (mEnterTransitionCoordinator != null) {
197                 startEnter();
198             }
199         }
200     }
201 
startEnter()202     private void startEnter() {
203         if (mEnterActivityOptions.isReturning()) {
204             if (mExitingToView != null) {
205                 mEnterTransitionCoordinator.viewInstancesReady(mExitingFrom, mExitingTo,
206                         mExitingToView);
207             } else {
208                 mEnterTransitionCoordinator.namedViewsReady(mExitingFrom, mExitingTo);
209             }
210         } else {
211             mEnterTransitionCoordinator.namedViewsReady(null, null);
212             mEnteringNames = mEnterTransitionCoordinator.getAllSharedElementNames();
213         }
214 
215         mExitingFrom = null;
216         mExitingTo = null;
217         mExitingToView = null;
218         mEnterActivityOptions = null;
219     }
220 
onStop()221     public void onStop() {
222         restoreExitedViews();
223         if (mEnterTransitionCoordinator != null) {
224             mEnterTransitionCoordinator.stop();
225             mEnterTransitionCoordinator = null;
226         }
227         if (mReturnExitCoordinator != null) {
228             mReturnExitCoordinator.stop();
229             mReturnExitCoordinator = null;
230         }
231     }
232 
onResume()233     public void onResume() {
234         restoreExitedViews();
235     }
236 
clear()237     public void clear() {
238         mEnteringNames = null;
239         mExitingFrom = null;
240         mExitingTo = null;
241         mExitingToView = null;
242         mCalledExitCoordinator = null;
243         mEnterTransitionCoordinator = null;
244         mEnterActivityOptions = null;
245         mExitTransitionCoordinators = null;
246     }
247 
restoreExitedViews()248     private void restoreExitedViews() {
249         if (mCalledExitCoordinator != null) {
250             mCalledExitCoordinator.resetViews();
251             mCalledExitCoordinator = null;
252         }
253     }
254 
startExitBackTransition(final Activity activity)255     public boolean startExitBackTransition(final Activity activity) {
256         if (mEnteringNames == null) {
257             return false;
258         } else {
259             if (!mHasExited) {
260                 mHasExited = true;
261                 Transition enterViewsTransition = null;
262                 ViewGroup decor = null;
263                 boolean delayExitBack = false;
264                 if (mEnterTransitionCoordinator != null) {
265                     enterViewsTransition = mEnterTransitionCoordinator.getEnterViewsTransition();
266                     decor = mEnterTransitionCoordinator.getDecor();
267                     delayExitBack = mEnterTransitionCoordinator.cancelEnter();
268                     mEnterTransitionCoordinator = null;
269                     if (enterViewsTransition != null && decor != null) {
270                         enterViewsTransition.pause(decor);
271                     }
272                 }
273 
274                 mReturnExitCoordinator =
275                         new ExitTransitionCoordinator(activity, mEnteringNames, null, null, true);
276                 if (enterViewsTransition != null && decor != null) {
277                     enterViewsTransition.resume(decor);
278                 }
279                 if (delayExitBack && decor != null) {
280                     final ViewGroup finalDecor = decor;
281                     decor.getViewTreeObserver().addOnPreDrawListener(
282                             new ViewTreeObserver.OnPreDrawListener() {
283                                 @Override
284                                 public boolean onPreDraw() {
285                                     finalDecor.getViewTreeObserver().removeOnPreDrawListener(this);
286                                     if (mReturnExitCoordinator != null) {
287                                         mReturnExitCoordinator.startExit(activity.mResultCode,
288                                                 activity.mResultData);
289                                     }
290                                     return true;
291                                 }
292                             });
293                 } else {
294                     mReturnExitCoordinator.startExit(activity.mResultCode, activity.mResultData);
295                 }
296             }
297             return true;
298         }
299     }
300 
startExitOutTransition(Activity activity, Bundle options)301     public void startExitOutTransition(Activity activity, Bundle options) {
302         if (!activity.getWindow().hasFeature(Window.FEATURE_ACTIVITY_TRANSITIONS)) {
303             return;
304         }
305         ActivityOptions activityOptions = new ActivityOptions(options);
306         mEnterTransitionCoordinator = null;
307         if (activityOptions.getAnimationType() == ActivityOptions.ANIM_SCENE_TRANSITION) {
308             int key = activityOptions.getExitCoordinatorKey();
309             int index = mExitTransitionCoordinators.indexOfKey(key);
310             if (index >= 0) {
311                 mCalledExitCoordinator = mExitTransitionCoordinators.valueAt(index).get();
312                 mExitTransitionCoordinators.removeAt(index);
313                 if (mCalledExitCoordinator != null) {
314                     mExitingFrom = mCalledExitCoordinator.getAcceptedNames();
315                     mExitingTo = mCalledExitCoordinator.getMappedNames();
316                     mExitingToView = mCalledExitCoordinator.copyMappedViews();
317                     mCalledExitCoordinator.startExit();
318                 }
319             }
320         }
321     }
322 }
323